text: A pulsed field gradient is a short, timed pulse with spatial-dependent field intensity. Any gradient is identified by four characteristics: axis, strength, shape and duration.
  Pulsed field gradient (PFG) techniques are key to magnetic resonance imaging, spatially selective spectroscopy and studies of diffusion via diffusion ordered nuclear magnetic resonance spectroscopy (DOSY). PFG techniques are widely used as an alternative to phase cycling in modern NMR spectroscopy.